JP2013010158A - Automatic clamp method for ingot block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of grinding debris to be produced when applying cylindrical grinding to the outer peripheral face of an cylindrical sapphire ingot block.SOLUTION: Auto loader equipment 13 is used for clamping devices 7a, 7b to automatically clamp a workpiece. After the workpiece is clamped once, height measuring equipment HS is used for measuring the height of the outer peripheral face of the clamped workpiece, and after the workpiece is re-clamped to move its C-axis position by a value (H-H)/2 half a difference between a maximum height (H) and a minimum height (H), a cup wheel type grinding wheel 10g is used for starting the in-feed cylindrical grinding of the workpiece.

Description

  In the present invention, after holding an ingot block using a hand claw of an autoloader (automatic loading device), the ingot block is loaded into a clamping device including a headstock and a tailstock, and then both ends of the C-axis of the ingot block are connected to each other. The present invention relates to an automatic clamping method of an ingot block at the time of suspension. The ingot block that is correctly supported by the clamping device is a chamfered surface by 0.5-8 mm thickness grinding by relative movement of the rotating cup wheel type grindstone and the ingot block, and the surface is smooth. Is done.

  Single crystal silicon substrates such as DRAM, SOI substrates, solar power generation substrates, sapphire substrates for LED substrates, and cylindrical ingot blocks made of materials such as GaAs substrates are single crystal silicon ingots grown by the Czochralski method (CZ method), Alternatively, the crystal direction of the compound semiconductor ingot grown by the Bernoulli method is measured with an X-ray analyzer, and if necessary, a cylindrical rod is created, and this cylindrical ingot is supported on a clamp device comprising a headstock and a tailstock. The crystal direction of the ingot is measured with an X-ray analyzer, and the length of the cylindrical ingot is 250 mm, 500 mm, or 1,000 mm with a slicing device such as a diatom, an inner peripheral blade, or a wire saw in a crystal direction perpendicular to the C-axis direction. Cut and chamfered column ingot block manufacturer or semiconductor substrate manufacturer It has been supplied. The diameters of the cylindrical ingot blocks are 2 inches, 4 inches, 6 inches, 8 inches, and 12 inches available from the market.

  The cylindrical ingot block is chamfered on the outer peripheral portion in order to prevent cracking or chipping of the outer periphery of the ingot block when slicing to a thickness of 200 to 900 μm by the wire cut saw of the ingot block. As a chamfering method, an etching method, a CMP polishing method, and a cylindrical grinding method using a cup wheel type grindstone are carried out.

JP 2009-233819 A (Patent Document 1) marks a crystal direction on a single crystal silicon ingot whose crystal direction is detected by the X-ray analyzer, and the marked single crystal silicon ingot block is
Clamp device comprising a headstock and a tailstock, a cylindrical grinding wheel movable in the rotation axis (C-axis) direction (left-right direction) of the single crystal silicon ingot block, and an orientation flat and / or notch on the single crystal ingot block It consists of a grindstone for processing, a camera that captures an image of the side surface of the single crystal ingot marked with a crystal line as a reference, and a controller that processes the captured image, and recognizes and stores the position of the mark Sandwiched by the clamping device of the single-crystal ingot cylindrical grinding device comprising: an image processing means for performing X-ray diffraction measurement of the crystal orientation of the single crystal ingot;
The position of the mark added in advance is stored by the image processing means, and the cylindrical grinding wheel is moved in the direction of the axis of rotation of the ingot while rotating the ingot around the axis by the clamp device to move the side surface of the ingot. After cylindrical grinding
X-ray diffraction measurement of the crystal orientation of the ingot is performed by the X-ray diffractometer, the position of a predetermined crystal orientation is specified from the measured diffraction peak with the position of the mark as a reference, and the arbitrary position with reference to the specified position A cylindrical grinder for a single crystal ingot block that performs orientation flat and / or notch processing with the above-mentioned grindstone at a position is proposed.

The cylindrical ingot block is chamfered on the outer peripheral portion in order to prevent cracking or chipping of the outer periphery of the ingot block when slicing to a thickness of 200 to 900 μm by the wire cut saw of the ingot block. As a chamfering method, an etching method, a CMP polishing method, and a cylindrical grinding method using a cup wheel type grindstone are carried out.

  When a cylindrical ingot block with a smooth chamfered surface is used for a photovoltaic power generation plate, both ends of the C-axis of the cylindrical ingot block are supported on a clamp device composed of a headstock and a tailstock and rotated. The surface is chamfered by a thickness grinding process of 0.5 to 8 mm by relative movement of the cup wheel type grindstone and the ingot block in the left-right direction, and the surface is made into a smooth ingot block.

The patent applicant of the present application is described in Japanese Patent Application No. 2010-251383 (Patent Document 2).
a) Work table provided on the machine frame (base) so as to be able to reciprocate in the left-right direction on a guide rail provided in the left-right direction b) A headstock mounted separately on the work table on the left and right A clamping mechanism comprising a pair of tailstocks,
c) A drive mechanism for reciprocating the work table on which a work (rectangular prism-shaped ingot) supported by the clamp mechanism is mounted in a horizontal direction;
d) The work table is viewed from the front side at a right angle, and from the left side to the right side,
e) a first grinding stage provided in front of and behind the work table with a pair of cup wheel type grindstones supported by a pair of grindstone axes movable back and forth sandwiching the work table so that the grindstone surfaces face each other;
f) A pair of cup wheel type grindstones mounted parallel to the right side of the first grinding stage and supported by a pair of grindstone shafts that can move back and forth are sandwiched between the work tables so that the grindstone surfaces face each other. A second grinding stage provided before and after the worktable,
g) a load port provided with an opening that allows a workpiece to be transferred to and from the clamp mechanism in a housing material located on the right side of the second grinding stage and on the front side of the work table;
and,
h) On the rear side of the work table facing the load port, a grinding wheel shaft having a grinding wheel is parallel to the horizontal direction of the work table, and the grinding wheel shaft is movable in the front-rear direction. R corner grinding stage provided above,
We proposed a chamfering machine characterized by the provision of

  JP-A-2009-55039 (Patent Document 3) also describes that after a cylindrical silicon block is chamfered with a band saw to form a prismatic silicon block, a side surface is formed with a cup wheel type grindstone having an abrasive grain size of 80 to 60 μm. We propose a method of manufacturing a square wafer by rough grinding, then finish grinding the side surface with a cup wheel grindstone with an abrasive grain size of 3 to 40 μm, etching the surface, and then slicing the surface. .

JP 2009-233819 A Japanese Patent Application No. 2010-251483 (not disclosed) JP 2009-55039 A

As a result of Prime Minister Aso's Earth Green Industry policy and President Obama's Green Newdale policy, solar power generation boards and LED substrates have attracted attention, and the shortage of supply of cylindrical silicon blocks and sapphire cylindrical ingot blocks is considered a problem. In the second half of 2010, the appearance of a chamfering processing apparatus with less generation of grinding waste is desired by the semiconductor substrate industry.

Semiconductor substrate manufacturers to use a cylindrical grinding apparatus described in Patent Document 1, chamfering allowance of the cylindrical ingot block (t _e) is set to less chamfering programs and 0.5 to 1.5 mm, the controller of the machining program (Numerical control device) The data is stored in the memory unit, and after the processor holds the both ends of the C-axis of the cylindrical ingot block between the clamping devices, the chamfering operator of the cylindrical ingot block uses a hammer to hold the cylindrical ingot block. The chamfering of the cylindrical ingot block using the grinding wheel is started after the C-axis position of the cylindrical ingot block with respect to the workpiece support shaft of the clamping device is matched with the grinding wheel starting position height of the grinding wheel.

  This method of correcting the position where the cylindrical ingot block is clamped (supported) in the clamping device has the advantage that the amount of generated grinding scraps used for regeneration is reduced. However, since the clamping position is corrected manually by hitting the cylindrical ingot block with a hammer, the C-axis correction position is not accurate and the outer circumference is insufficient in some of the cylindrical ingot blocks that have been chamfered. Since a columnar ingot block is found and this causes loss substrate generation, it is rotated as a reprocessed product, causing a reduction in substrate production rate. For example, in the case of a sapphire substrate, if the crystal orientation direction angle with respect to the orientation flat angle of the sapphire substrate having a thickness of 0.2 to 1.0 mm obtained by slicing a cylindrical ingot block by the wire cut method exceeds 0.5 degrees, a sapphire substrate is obtained. This is because it is treated as a defective product.

The inventors have used an autoloader device and a clamp device used in the chamfering apparatus for an ingot block described in Patent Document 2, and changed an automatic clamp program to the clamp device for the ingot block (workpiece) to change the workpiece. Is gripped by the robot claw of the autoloader device, loaded into the clamping device and supported, and the outer peripheral position height (H _r , H _l ) in the vicinity of both ends of the supported work is measured. Assuming that the defect rate can be reduced by correcting the clamping position of the C-axis position of the ingot block to the support shaft of the clamping device by a half amount of the difference in height (H _r -H _l ), The present invention has been reached.

Claim 1 of the present invention grips the central portion of a cylindrical ingot block (work) having a diameter of Rmm and a grinding allowance (t) setting of t _g mm thickness with a robot claw of an autoloader device,
The work gripped by the robot claw is carried between the headstock and the tailstock constituting the clamping device,
After the tailstock is advanced and both ends in the longitudinal direction (C-axis direction) of the workpiece are supported by the clamp device, the robot claw of the autoloader device is moved away from the workpiece and both ends of the workpiece supported by the clamp device Measure the peripheral height (H _r , H _l ) in the vicinity while rotating the workpiece 360 degrees around the C axis on the headstock using a height measuring instrument,
Calculate the ½ amount of the difference (H _h −H _m ) between the maximum value and the minimum value of the outer peripheral position height from the two C-axis measured.
Next, after gripping the center of the workpiece with the robot claw of the autoloader device, the tailstock of the clamp device is retracted to release the workpiece,
Support shaft (C axis) of the clamp device for moving the C-axis position of the ingot block by a half amount of the calculated (H _h -H _m ) of the work held by the robot claw of the autoloader device After the correction to, the tailstock is moved forward and supported on the clamping device, and the robot claw is moved away from the workpiece,
The height (H _r , H _l ) of the outer peripheral position in the vicinity of both ends of the supported work is measured while rotating the work 360 degrees around the C axis on the headstock using a height measuring device,
The value of the maximum value of the peripheral position height from C axis of the measured two points _{(H h)} and minimum value _{(H m) (H h,} H m) are both _{(R / 2-t g)} mm If it is above, it sends a signal of automatic clamping end to the workpiece clamping device, and starts chamfering grinding of the cylindrical ingot block by the cup wheel type grindstone in the next process,
The value of the outer peripheral position height of at least one of the maximum value (H _h ) and the minimum value (H _m ) (H _h , H _m ) of the outer peripheral position height from the two measured C axes. Is less than (R / 2−t _g ) mm, an automatic clamping failure signal is transmitted to the workpiece clamping device, the center portion of the workpiece is gripped by the robot claw of the autoloader device, and then the tailstock To move the robot claw and move the workpiece out of the clamping device.
An automatic clamping method for an ingot block is provided.

The method for automatically clamping a cylindrical ingot block using the autoloader device according to the present invention has the possibility of chamfering with a grindstone of the ingot block on the clamp device even if the ingot block has a small grinding allowance (t _g ). Therefore, the ingot block is not given an opportunity for grinding. Moreover, since the grinding allowance ( _tg ) is small, the generation amount of chamfering process waste can be reduced.

FIG. 1 is a perspective view of the chamfering apparatus described in Patent Document 2 as seen from an angle of about 15 degrees obliquely to the left front side. FIG. 2 is a plane surface of the chamfering apparatus described in Patent Document 2. FIG. 3 is a right side surface of the chamfering apparatus described in Patent Document 2. FIG. 4 is a plan view showing a state where the ingot block is clamped to the clamping device in the chamfering processing device described in Patent Document 2, and the autoloader device is omitted. FIG. 5 is a step diagram for automatically clamping the ingot block to the clamping device. FIG. 6 is a flow sheet for automatically clamping an ingot block to a clamping device.

  In order to describe the autoloader device 13 and the clamp device 7, the chamfering device 1 described in Patent Document 2 shown in FIGS. 1, 2, 3 and 4 will be described. The chamfering apparatus 1 is provided with a work table 4 provided so as to be able to reciprocate in a left-right direction on a pair of guide rails 3, 3 laid on a machine frame (base) 2 in a left-right direction. When the work table 4 is reciprocated left and right, the ball screw 6 receives rotation driven by the servo motor 5 and rotates, and a fixing base (not shown) screwed to the ball screw advances leftward or rightward. As a result, the work table 4 having the back surface of the work table 4 fixed to the surface of the fixed base advances in the left direction or the right direction. The advancement of the work table 4 in the left direction or the right direction depends on whether the rotation shaft of the servo motor 5 is clockwise or counterclockwise.

A clamp mechanism 7 comprising a pair of a headstock 7a and a tailstock 7b mounted separately on the work table 4 is mounted. Therefore, the clamping mechanism 7 in association with the movement of the left or right of the work table 4 is also moved to the left or right direction, the headstock center support shaft 7a ₁ and the tailstock center support shaft 7b of the clamping mechanism 7 _The workpiece (columnar or prismatic ingot block) w that is suspended (clamped) by ₁ and suspended is moved to the R-corner grinding stage 9, the first grinding stage 10, the second grinding stage 11, or the load port 8 position. It is possible to move.

As shown in Patent Document 1, the clamp device 7 is a known chuck mechanism and is often used in a cylindrical grinder. Headstock 7a has a function of rotating the workpiece w 360 degrees or 90 degrees by rotating the headstock center support shaft 7a ₁ by the servo motor 7a _m. Tailstock 7b is provided on the movable table 7b _t which can be moved on the guide rails with an air cylinder 7e drive the left and right, after支架the workpiece by the clamp mechanism 7, and fixed by depressing the lever, movement of the work table 4 moving base 7b _t for mounting the tailstock 7b is prevented from moving by.

  The positional relationship among the R corner portion grinding stage 9, the first grinding stage 10, the second grinding stage 11, and the load port 8 is a direction in which the work table 4 is viewed from a right angle from the front side and from the left side direction. A first grinding stage 10, a second grinding stage 11, and a load port 8 are provided toward the right side, and an R corner portion grinding stage 9 is provided on the back surface of the load port 8. The R corner portion grinding stage 9, the first grinding stage 10 and the second grinding stage 11 are covered with a hermetic cover 12. The load port 8 is closed by a one-hand side sliding door 12a. An exhaust duct 13 is connected to the space of each grinding stage 9, 10, 11 covered with the hermetic cover 12, and mist and grinding debris floating in this space are discharged to the outside.

The first grinding stage 10 is composed of a cup wheel type grindstone or a ring-shaped grindstone supported by a pair of grindstone shafts 10a, 10a provided on tool tables 10t, 10t that can be moved back and forth by rotation of servo motors 10m, 10m. provided at a position where the pair 10 g, the grinding wheel surface _{10 g} s a 10 g, 10 g _s is and symmetrically around the work table 4 across the work table 4 so as to face each other grinding wheel axis ₁₀ o, 10 _o is collinear these wheel spindle 10a, 10a has a structure that is rotated by the rotational driving of the servo motor ₁₀ M, 10 _M.

  When the ball screw receives rotation by the servo motors 10m and 10m and rotates, and the fixing table screwed to the ball screw advances or retracts forward or backward, the tool tables 10t and 10t are placed on the surface of the fixing table. The tool tables 10t and 10t whose back surfaces are fixed move forward or backward. The forward or backward movement direction of the tool table depends on whether the rotation shafts of the servo motors 10m and 10m are clockwise or counterclockwise.

The second grinding stage 11 is a cup wheel type grindstone or ring-shaped grindstone supported by a pair of grindstone shafts 11a, 11a provided on tool tables 11t, 11t that can be moved back and forth by the rotational drive of servo motors 11m, 11m. We provided at a position where the pair 11g, the grinding wheel surface _11g s to 11g, 11g _s is and symmetrically around the work table 4 across the work table 4 so as to face each other grindstone axis ₁₁ o, 11 _o is collinear these wheel spindle 11a, 11a has a structure that is rotated by the rotational driving of the servo motor ₁₁ M, 11 _M.

When the ball screw receives the rotation drive by the servo motors 11m and 11m and rotates, and the fixed base screwed into the ball screw moves forward or backward in the forward or backward direction, the tool table 11t, The tool tables 11t and 11t to which the back surface of 11t is fixed move forward or backward. The forward or backward movement direction of the tool table depends on whether the rotation shafts of the servomotors 11m and 11m are clockwise or counterclockwise.

The second grinding stage 11 is provided in parallel to the right side of the first grinding stage 10. That is, the grindstone axes 10 _o and 11 _{o of} both the stages 10 and 11 are parallel.

  Note that the grindstone used in the first grinding stage 10 and the grindstone used in the second grinding stage 11 may be either rough grinding wheels or precision finish grinding wheels. The figure shows an example in which the grindstone used in the first grinding stage 10 is a rough grinding grindstone 10 g, and the grindstone used in the second grinding stage 11 is a precision finish grinding grindstone 11 g.

  The diameter of the grinding wheel 10g, 10g, 11g, and 11g is a wheel diameter of 240 to 60 mm when the square ingot block for a solar cell silicon substrate with a side of 150 mm is intended. Is preferably 3 to 10 mm and the ring-shaped grindstone width is 5 to 15 mm from the viewpoint of preventing grinding and burning of the silicon ingot. The distance (radius) from the center point of the wheel to the outer periphery of the wheel width is the same radius for one or two of the rough grinding wheels and two of the precision finish grinding wheels, but the average roughness Ra of the ingot chamfer finish surface is It will be good. Further, the cup wheel type grindstone diameters of the pair of coarse grinding wheels 10g, 10g may be the same or one diameter may be 5 to 20 mm shorter than the other diameter. When the workpiece is a cylindrical ingot block for a sapphire substrate having a size of 2 to 6 inches, the diameter of the grinding wheel 10g, 10g, 11g, 11g is 100 to 240 mm.

  The abrasive grains of the grinding wheels 10g and 11g are preferably diamond abrasive grains and CBN abrasive grains, and the binder is preferably a metal bond, vitrified bond, or epoxy resin bond. For example, a cup wheel type rough grinding wheel 10g is a lower annular shape of a bottomed cylindrical grinding wheel base metal disclosed in, for example, Japanese Patent Laid-Open Nos. 9-38866, 2000-94342, and 2004-167617. A cup wheel type grindstone in which a large number of grindstone blades are annularly arranged in a ring with a gap interval at which the grinding liquid dissipates, and the structure in which the grinding liquid supplied to the inside of the base metal is dissipated from the gap is preferable. The diameter of the annular grindstone blade of the cup wheel type grindstone 10g is preferably 1.2 to 1.5 times the length of one side of the prismatic silicon ingot. The ring wheel of the cup wheel type rough grinding wheel is preferably a diamond resin bond grindstone having a grind number of 100 to 280 or a diamond vitrified bond grindstone. The ring wheel of the cup wheel type precision finish grinding wheel 11g is preferably a diamond resin bond grindstone, a diamond vitrified bond grindstone, or a diamond metal bond grindstone with a grind number of 300 to 1,200. Further, as the grinding wheel 9g described later, a diamond grinding wheel having a grinding number of 300 to 1,200 is preferable.

  As the grinding liquid, pure water, colloidal silica water dispersion, ceria water dispersion, SC-1 liquid, SC-2 liquid, or pure water and these water dispersion or grinding liquid are used in combination. As the grinding liquid, it is preferable to use only pure water from the viewpoint of water treatment considering the environment.

  The load port 8 is formed by providing an opening that allows the workpiece w to be transferred into and out of the clamping device 7 in the housing material located on the right side of the second grinding stage 11 and on the front side of the work table 4. Is done.

The R corner portion grinding stage 9 has a grinding wheel shaft 9a having a grinding wheel 9w on the rear side of the work table 4 facing the load port 8, parallel to the horizontal direction of the work table 4, and the grinding wheel shaft 9a A structure in which the shaft core 9 _o is provided on the tool table 9 t so as to be movable in the front-rear direction is adopted.

Rotation of the wheel spindle 9a is performed by the rotation of the servomotor 9 _M, forward and backward in the tool table 9t rotates by receiving the rotational driving by the servo motor 9m ball screw, fixing base which is screwed to the ball screw is By moving forward or backward in the forward or backward direction, the tool table 9t having the back surface of the tool table 9t fixed to the fixed base surface moves forward or backward on the guide rails 9r and 9r. The forward or backward movement direction of the tool table depends on whether the rotation shaft of the servo motor 9m is clockwise or counterclockwise.

  In FIG. 1, reference numeral 20 denotes a control device, and reference numeral 21 denotes an operation panel. Moreover, in FIG. 2, the code | symbol 9c shows a grinding fluid supply pipe | tube.

  As shown in FIGS. 1, 2, and 3, a chamfering apparatus 1 for a cylindrical ingot block (work) is a front side of the work table 4 and a space between the load port 8 and the second grinding stage 10. An autoloader (workloading / unloading device) 13 and a work stocker 14 for storing three ingot blocks are juxtaposed on the machine frame 2. Reference numeral 15 denotes a spare work stocker placed on the table of the transport carriage 16 provided with a stepladder.

  The work stockers 14 and 15 are provided with V-shaped shelves having an inverted isosceles triangle shape capable of storing three ingot blocks (work pieces) w, w, and w inclined at 45 degrees, and positioning pins 16 protruding from the machine frame. It is placed on top.

  The autoloader device (workloading / unloading device) 13 holds one ingot block (workpiece) w stored in a work stocker 14V-shaped shelf with a pair of claws 13a and 13b and raises both claws. The workpiece is lifted, and then moved backward, moved rightward, lowered to be positioned in front of the load port 8, and further moved backward to move the workpiece from the headstock 7a and the tailstock of the clamping device 7. 7b. After one end of the work is brought into contact with the center support shaft 7a1 of the headstock 7a, the tailstock 7b is moved to the right by the air cylinder 7e, and the other end is brought into contact with the center support shaft 7b1 so that the work is 45 degrees V. Inclined and suspended on 4 sides suspended. Next, the claws 13a and 13b are separated to release the workpiece, and then the fixing base 13f supporting the claws 13a and 13b is lifted, moved to the left, and further moved backward to move both claws. 13a and 13b are returned to the standby position.

  Further, the chamfering process and the cleaned and air-dried work supported in a suspended state in the clamp device 7 are gripped by both claws 13a and 13b, and then the fixing base 13f supporting both the claws 13a and 13b is raised, After moving the claw 13a, 13b above the empty shelves of the work stockers 14, 15 after moving the claw 13a, 13b to the left and moving the claw 13a, 13b downward, , 13b are separated and the workpiece is released, and then the claws 13a, 13b are returned to the standby position.

The fixed base 13f that supports the claws 13a and 13b is moved in the front-rear direction by providing, on the side surface of the column 13c, the sliding surface 13s of the fixed base 13f that is screwed back to the ball screw 13k that is rotationally driven by the servo motor 13m. This is done by sliding on the guide rail 13g. The vertical movement of the fixing base 13f that supports the claws 13a and 13b is performed by the air cylinder 13p. The two claws 13a and 13b are separated from each other by using a micro week air cylinder 13e shown in a circle of FIG. Fine adjustment of the slight raising and lowering of the claws 13a and 13b is performed using a micro week air cylinder 13l. Both pawls 13a, fine adjustment of a small back-and-forth movement of the 13b is performed using a micro weak air cylinder 13 _R.

The cylindrical ingot block w stored in the work stockers 14 and 15 installed in the chamfering processing device 1 for the ingot block is used for the support shafts 7a ₁ and 7b of the clamping device 7 by using the robot claws 13a and 13b of the autoloader device 13. _The process of automatically clamping (supporting) ₁ is performed as follows.

Robot claw 13a of the autoloader devices 13, diameter 13b is Rmm, grinding allowance (t) set to grip the central portion of the cylindrical ingot block (work) of _t g mm thickness. S01

Wherein the gripped workpiece to the robot claws and carried into between the support shaft 7b ₁ of the support shaft 7a ₁ and tailstock 7b headstocks 7a, the longitudinal axis (C axis of the workpiece w by advancing the tailstock 7b Both ends in the direction) are supported by the support shafts 7a ₁ and 7b ₁ of the clamp device 7. Note that a line connecting both shaft cores of the support shafts 7a ₁ and 7b ₁ is called a C-axis center of the clamp device 7. S02

  The robot claws 13a and 13b of the autoloader device 13 are moved away from the workpiece w. S03

The outer peripheral position height (H _r , H _l ) in the vicinity of both ends of the workpiece w supported by the clamp device 7 is used as a height measuring device HS (for example, touch probe sensor ΣD (trade name) of Tokyo Seimitsu Co., Ltd., Nikon Corporation) The workpiece is measured while being rotated 360 degrees around the C axis on the headstock using a leather-type displacement sensor device or an image pickup apparatus equipped with a CCD camera disclosed in Patent Document 1. S04

The numerical controller calculates a ½ amount of the difference (H _h −H _m ) between the maximum value (H _h ) and the minimum value (H _m ) of the outer peripheral position height from the two C-axis measured. Part. S05

Further, the distance between the C axis of the clamp device 7 and the grinding start point position of the cup wheel type grindstone 10g (R / 2−t _g ) and the minimum value (H _m ) are compared in the comparison unit of the numerical controller. Then, the value of (R / 2−t _g −H _m ) is a positive direction, and the C axis of the workpiece is moved on a plane including the C axis of the clamp device 7 and the height measuring device HS. Decide the direction. S06

  After the center of the workpiece w is gripped by the robot claws 13a and 13b of the autoloader device 13, the tailstock 7b of the clamping device 7 is retracted to release the workpiece. S07

Support axis (C-axis) of the clamp device for moving the C-axis position of the ingot block by a half amount of the calculated (H _h -H _m ) of the work held by the robot claw of the autoloader device ). S08

The tailstock 7b is moved forward to be supported on the support shafts 7a ₁ and 7b ₁ of the clamp device 7. S09

  The robot claws 13a and 13b are moved away from the workpiece w. S10

The height of the outer peripheral position (H _r , H _l ) in the vicinity of both ends of the supported work w is rotated 360 degrees around the C axis by the servo motor of the headstock 7a using the height measuring device HS. Measure while. S11

The value of the maximum value of the peripheral position height from C axis of the measured two points _{(H h)} and minimum value _{(H m) (H h,} H m) are both _{(R / 2-t g)} mm If it is above, the signal of the completion | finish of automatic clamping to the clamp apparatus 7 of a workpiece | work will be transmitted, and S12a will start the infeed chamfering grinding process of the cylindrical ingot block by the cup wheel type grindstone of the next process. S13

The value of the outer peripheral position height of at least one of the maximum value (H _h ) and the minimum value (H _m ) (H _h , H _m ) of the outer peripheral position height from the two measured C axes. Is less than (R / 2−t _g ) mm, an automatic clamping failure signal is sent to the workpiece clamping device, and the center portion of the workpiece w is gripped by the robot claws 13a and 13b of the autoloader device 13 in S12b. Thereafter, the tailstock 7b is moved backward to release the support by the workpiece clamping device 7, and then the robot claws 13a and 13b are moved to the workpiece stocker 14 (the workpiece is conveyed out of the clamping device 7). S14

The chamfering grinding process of the cylindrical ingot block by the cup wheel type grindstone 10g in the step S13 is performed while moving the clamp mechanism 7 that supports the ingot block suspended in the left-right direction at a speed of 1 to 15 mm / min, The center support shaft 7a ₁ is rotated at a rotational speed of ₁₀ to 300 rpm, and a pair of 10 g and 10 g of the grinding wheel shaft rotating at a rotational speed of 800 to 3,000 rpm is connected to the C axis side of the clamp device 7. is advanced cup wheel type grindstone 10g, and the infeed edge position of 10g from C axis of the clamping device 7 to (R / 2-t _g) distance (grinding start point position) to start the grinding to, While supplying the grinding fluid to the grinding work point in an amount of 5 to 100 cc / min, the cup wheel grindstone is transferred by a pair of 10 g and 10 g. The ingot block peripheral surface thickness of a infeed cylindrical grinding of allowance removal amount of t _g mm.

  Cylindrical cylindrical ingot block (work) w Examples of commercially available materials include single crystal silicon ingot blocks having a diameter of 8 to 12 inches, sapphire ingot blocks having a diameter of 2 to 6 inches, and GaAs ingot blocks. . The work length is 100 to 1,000 mm.

The grinding allowance (t _g ) of the cylindrical ingot block (work) w by the cup wheel type grindstones 10g and 11g is 0.5 to 6 mm in the case of the silicon ingot block, and 0.5 in the case of the sapphire ingot block and the GaAs ingot block. -1.0 mm.

  The ingot block automatic clamping method of the present invention can be used in a cylindrical grinding apparatus that performs cylindrical grinding using a pair of cup wheel type grinding wheels 10g, 10g described in Patent Document 2, or one cylindrical grinding described in Patent Document 1. The present invention can also be adopted in a cylindrical grinding apparatus that cylindrically grinds a cylindrical ingot block with a grindstone.

Since the cylindrical ingot block w determined to have an automatic clamping failure in the above-described step S12b is recovered without being subjected to cylindrical grinding, the grinding amount (t) is set to a value larger than the set grinding amount (t _g ). Can be reused as a cylindrical grinding material.

The automatic clamping method of the cylindrical ingot block w using the autoloader device 13 of the present invention is such that the ingot block is chamfered with a grinding wheel on the clamping device 7 even if the ingot block has a small grinding allowance (t _g ). The possibility of grinding can be evaluated, so that the defective ingot block is not given an opportunity for grinding. Moreover, since the grinding allowance ( _tg ) is small, the generation amount of chamfering process waste can be reduced.

DESCRIPTION OF SYMBOLS 1 Chamfering processing apparatus w Cylindrical ingot block 7 Clamp mechanism 7a Shaft base 7b Tailstock 8 Load port 10 First grinding stage 11 Second grinding stage 13 Autoloader equipment 14 Work stocker HS Height measuring equipment

Claims (1)

Diameter robot claws autoloader devices Rmm, grinding allowance (t) set to grip the central portion of the cylindrical ingot block of t _g mm thickness,
A cylindrical ingot block held by the robot claw is carried between the headstock and the tailstock constituting the clamp device,
After the tailstock is advanced and both ends in the longitudinal direction (C-axis direction) of the cylindrical ingot block are supported by the clamp device, the robot claw of the autoloader device is moved away from the cylindrical ingot block, and the clamp device The height of the outer peripheral position (H _r , H _l ) in the vicinity of both ends of the cylindrical ingot block supported on the shaft is measured by rotating the cylindrical ingot block 360 degrees around the C axis on the headstock using a height measuring device. ,
Calculate the ½ amount of the difference (H _h −H _m ) between the maximum value and the minimum value of the outer peripheral position height from the two C-axis measured.
Next, after gripping the center of the cylindrical ingot block with the robot claw of the autoloader device, retreat the tailstock of the clamp device to release the holding of the cylindrical ingot block,
The C-axis position of the cylindrical ingot block held by the robot claw of the autoloader device is ½ of the calculated (H _h −H _m ), and the C-axis position of the cylindrical ingot block is the support shaft of the clamp device. After performing correction for movement with respect to (C axis), the tailstock is moved forward to be supported on the clamp device, and the robot claw is moved away from the cylindrical ingot block,
Measure the outer peripheral position height (H _r , H _l ) in the vicinity of both ends of the supported cylindrical ingot block while rotating the workpiece 360 degrees around the C axis on the headstock using a height measuring device,
The value of the maximum value of the peripheral position height from C axis of the measured two points _{(H h)} and minimum value _{(H m) (H h,} H m) are both _{(R / 2-t g)} mm If it is above, a signal of automatic clamping end to the clamping device of the cylindrical ingot block is transmitted, and chamfering grinding processing of the cylindrical ingot block by the cup wheel type grindstone in the next process is started.
The value of the outer peripheral position height of at least one of the maximum value (H _h ) and the minimum value (H _m ) (H _h , H _m ) of the outer peripheral position height from the two measured C axes. Is less than (R / 2−t _g ) mm, an automatic clamping failure signal is transmitted to the clamping device of the cylindrical ingot block, and the central portion of the cylindrical ingot block is moved by the robot claw of the autoloader device. After gripping, the tailstock is retracted to release the support of the cylindrical ingot block, and then the robot claw is moved to convey the cylindrical ingot block out of the clamping device.
An ingot block automatic clamping method characterized by the above.

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